In many computers, system firmware known as the basic input/output system (“BIOS”) begins executing prior to transferring control of the computer to the operating system. During this initial execution, the BIOS typically performs a series of routines known as the power-on self test (“POST”). Even after POST has completed and the operating system has booted, the BIOS continues to provide basic services as needed as long as the computer is powered on.
Among the basic services provided by the BIOS in some computers is to control the speed of cooling fans disposed within the computer enclosure. Assuming that the BIOS knows the maximum temperature at which a central processing unit (“CPU”) is rated by its manufacturer to operate, it can adjust fan speeds accordingly in response to the actual temperature sensed in the CPU at a given point in time. This is done so that fans can be run at lower rates of speed when it is possible to do so, thus reducing power consumption and lowering noise levels.
Currently, the BIOS is able to read registers within a CPU to determine the identity or model of the CPU. For example, existing registers might tell the BIOS that a CPU is an Intel Pentium IV. In order to make this information useful from a thermal management perspective, however, the BIOS must keep cross-reference tables so that it can determine the maximum temperature at which a particular CPU model is rated by its manufacturer to operate. When manufacturer specifications change for a given CPU model, or when new CPU models are introduced, the BIOS must be updated with new cross-reference tables.